Java 中裝飾者模式與策略模式在埋點系統中的應用

前言

在軟件開發中，裝飾者模式和策略模式是兩種常用的設計模式，它們在特定的業務場景下能夠發揮巨大的作用。本文將通過一個實際的埋點系統案例，探討如何在 Java 中運用裝飾者模式和策略模式，以及如何結合工廠方法模式來優化代碼結構。

業務場景分析

隨著互聯網的發展，用戶行為分析變得越來越重要，而埋點技術是實現用戶行為分析的關鍵手段之一。埋點系統需要記錄用戶在應用中的各種操作行為，如點擊、瀏覽、提交等，以便后續進行數據分析和業務決策。

假設我們正在開發一個在線教育平臺，需要實現以下埋點功能：

點擊埋點：記錄用戶點擊的位置。
課程埋點：記錄用戶點擊的課程信息。
任務埋點：記錄用戶點擊的任務信息。

這些埋點功能需要根據不同的業務場景進行動態組合，例如在課程頁面的點擊操作需要記錄點擊位置和課程信息，而在任務頁面的點擊操作需要記錄點擊位置和任務信息。

裝飾者模式的應用

裝飾者模式允許我們在不修改原有代碼的基礎上，動態地給對象添加職責。它由以下幾部分組成：

Component：定義對象的接口。
Concrete Component：實現 Component 接口的具體對象。
Decorator：維護一個對 Component 對象的引用，并定義與 Component 接口相同的接口。
Concrete Decorator：實現 Decorator 接口，負責給 Component 對象添加特定的職責。

實現埋點功能

// Component 接口
public interface SaveMessage {void saveMessage(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest);
}// Concrete Component：基礎點擊埋點
public class CommonClickPoint implements SaveMessage {@Overridepublic void saveMessage(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {pointSaveBean.setClickLocation(pointSaveRequest.getClickLocation());}
}// Decorator 抽象類
public abstract class AddPointMessageService implements SaveMessage {protected SaveMessage saveMessage;public AddPointMessageService(SaveMessage saveMessage) {this.saveMessage = saveMessage;}@Overridepublic void saveMessage(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {saveMessage.saveMessage(pointSaveBean, pointSaveRequest);}
}// Concrete Decorator：課程埋點
public class CourseClickPoint extends AddPointMessageService {public CourseClickPoint(SaveMessage saveMessage) {super(saveMessage);}@Overridepublic void saveMessage(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {super.saveMessage(pointSaveBean, pointSaveRequest);pointSaveBean.setCourseId(pointSaveRequest.getCourseId());}
}// Concrete Decorator：任務埋點
public class TaskClickPoint extends AddPointMessageService {public TaskClickPoint(SaveMessage saveMessage) {super(saveMessage);}@Overridepublic void saveMessage(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {super.saveMessage(pointSaveBean, pointSaveRequest);pointSaveBean.setTaskId(pointSaveRequest.getTaskId());}
}

客戶端代碼

public class CommonMain {public static void main(String[] args) {// 初始化埋點類型列表List<PointSaveType> types = Arrays.asList(PointSaveType.TASK, PointSaveType.COURSE);// 初始化埋點保存對象PointSaveBean pointSaveBean = new PointSaveBean();// 初始化埋點請求對象PointSaveRequest pointSaveRequest = PointSaveRequest.builder().pointSaveTypeList(types).clickLocation("右上角落").courseId("英語").taskId("任務1").build();// 初始化基礎保存邏輯SaveMessage saveMessage = new CommonClickPoint();saveMessage.saveMessage(pointSaveBean, pointSaveRequest);System.out.println("基礎埋點保存數據: " + pointSaveBean);// 根據埋點類型動態添加保存邏輯for (PointSaveType type : types) {if (type == PointSaveType.COURSE) {saveMessage = new CourseClickPoint(saveMessage);} else if (type == PointSaveType.TASK) {saveMessage = new TaskClickPoint(saveMessage);}saveMessage.saveMessage(pointSaveBean, pointSaveRequest);}// 打印最終埋點數據System.out.println("最終埋點保存數據: " + pointSaveBean);}
}

策略模式的應用

策略模式定義了一系列算法，并將每個算法封裝到具有共同接口的獨立類中，使它們可以互相替換。當埋點邏輯之間存在復雜的組合關系時，結合策略模式可以更好地管理這些組合邏輯。

實現埋點功能

// 策略接口
public interface PointSaveStrategy {void save(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest);
}// 具體策略：點擊埋點
public class ClickPointSaveStrategy implements PointSaveStrategy {@Overridepublic void save(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {pointSaveBean.setClickLocation(pointSaveRequest.getClickLocation());}
}// 具體策略：課程埋點
public class CoursePointSaveStrategy implements PointSaveStrategy {@Overridepublic void save(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {pointSaveBean.setCourseId(pointSaveRequest.getCourseId());}
}// 具體策略：任務埋點
public class TaskPointSaveStrategy implements PointSaveStrategy {@Overridepublic void save(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {pointSaveBean.setTaskId(pointSaveRequest.getTaskId());}
}// 策略上下文
public class PointSaveStrategyContext {private List<PointSaveStrategy> strategies = new ArrayList<>();public void addStrategy(PointSaveStrategy strategy) {strategies.add(strategy);}public void execute(PointSaveBean pointSaveBean, PointSaveRequest pointSaveRequest) {for (PointSaveStrategy strategy : strategies) {strategy.save(pointSaveBean, pointSaveRequest);}}
}// 策略配置
public class PointSaveStrategyConfig {private static final Map<PointSaveType, PointSaveStrategy> STRATEGY_MAP = new HashMap<>();static {STRATEGY_MAP.put(PointSaveType.CLICK, new ClickPointSaveStrategy());STRATEGY_MAP.put(PointSaveType.COURSE, new CoursePointSaveStrategy());STRATEGY_MAP.put(PointSaveType.TASK, new TaskPointSaveStrategy());}public static PointSaveStrategy getStrategy(PointSaveType type) {return STRATEGY_MAP.getOrDefault(type, null);}
}

客戶端代碼

public class CommonMain {public static void main(String[] args) {// 初始化埋點類型列表List<PointSaveType> types = Arrays.asList(PointSaveType.TASK, PointSaveType.COURSE);// 初始化埋點保存對象PointSaveBean pointSaveBean = new PointSaveBean();// 初始化埋點請求對象PointSaveRequest pointSaveRequest = PointSaveRequest.builder().pointSaveTypeList(types).clickLocation("右上角落").courseId("英語").taskId("任務1").build();// 創建策略上下文PointSaveStrategyContext context = new PointSaveStrategyContext();// 添加基礎策略context.addStrategy(new ClickPointSaveStrategy());// 根據埋點類型動態添加策略for (PointSaveType type : types) {PointSaveStrategy strategy = PointSaveStrategyConfig.getStrategy(type);if (strategy != null) {context.addStrategy(strategy);}}// 執行所有策略context.execute(pointSaveBean, pointSaveRequest);// 打印最終埋點數據System.out.println("最終埋點保存數據: " + pointSaveBean);}
}

工廠方法模式的結合

為了進一步簡化客戶端代碼，我們可以引入工廠方法模式來創建裝飾者對象。

// 工廠類
public class PointSaveDecoratorFactory {public static SaveMessage getDecorator(PointSaveType type, SaveMessage saveMessage) {switch (type) {case COURSE:return new CourseClickPoint(saveMessage);case TASK:return new TaskClickPoint(saveMessage);default:System.out.println("未知的埋點類型: " + type);return saveMessage;}}
}

客戶端代碼優化

public class CommonMain {public static void main(String[] args) {// 初始化埋點類型列表List<PointSaveType> types = Arrays.asList(PointSaveType.TASK, PointSaveType.COURSE);// 初始化埋點保存對象PointSaveBean pointSaveBean = new PointSaveBean();// 初始化埋點請求對象PointSaveRequest pointSaveRequest = PointSaveRequest.builder().pointSaveTypeList(types).clickLocation("右上角落").courseId("英語").taskId("任務1").build();// 初始化基礎保存邏輯SaveMessage saveMessage = new CommonClickPoint();saveMessage.saveMessage(pointSaveBean, pointSaveRequest);System.out.println("基礎埋點保存數據: " + pointSaveBean);// 根據埋點類型動態添加保存邏輯for (PointSaveType type : types) {saveMessage = PointSaveDecoratorFactory.getDecorator(type, saveMessage);saveMessage.saveMessage(pointSaveBean, pointSaveRequest);}// 打印最終埋點數據System.out.println("最終埋點保存數據: " + pointSaveBean);}
}